They were deprived by Constantine of all military command, as soon as they had ceased to lead into the field, under their immediate orders, the flower of the Roman troops; and at length, by a singular revolution, the captains of the guards were transformed into the civil magistrates of the provinces.

According to the plan of government instituted by Diocletian, the four princes had each their Praetorian praefect; and after the monarchy was once more united in the person of Constantine, he still continued to create the same number of Four Praefects, and intrusted to their care the same provinces which they already administered.1.The praefect of the East stretched his ample jurisdiction into the three parts of the globe which were subject to the Romans, from the cataracts of the Nile to the banks of the Phasis, and from the mountains of Thrace to the frontiers of Persia.2.The important provinces of Pannonia, Dacia, Macedonia, and Greece, once acknowledged the authority of the praefect of Illyricum.

3.
The power of the praefect of Italy was not confined to the country from whence he derived his title; it extended over the additional territory of Rhaetia as far as the banks of the Danube, over the dependent islands of the Mediterranean, and over that part of the continent of Africa which lies between the confines of Cyrene and those of Tingitania.

4.
The praefect of the Gauls comprehended under that plural denomination the kindred provinces of Britain and Spain, and his authority was obeyed from the wall of Antoninus to the foot of Mount Atlas.

[99] [Footnote 99: Zosimus, l.ii.p.109, 110.